上海市食源性金黄色葡萄球菌环丙沙星耐药性的形成与gyrA,grlA基因突变的相关性  

Correlation between Quinolones-resistance and Mutation of gyr A and grl A Genes in Food-borne Staphylococcus aureus Isolates from Shanghai

作　　者：徐洁[1] 施春雷[1] 许学斌[2] 宋明辉[1] 周敏[1,3] 史贤明[1] 

机构地区：[1]上海交通大学农业与生物学院中美食品安全联合研究中心微生物代谢国家重点实验室,上海200240 [2]上海市疾病预防控制中心,上海200336 [3]武汉轻工大学食品科学与工程学院,武汉430023

出　　处：《中国食品学报》2015年第11期148-153,共6页Journal of Chinese Institute Of Food Science and Technology

基　　金：国家863课题(2012AA101601);高等学校博士学科点专项科研基金项目(20120073110052);国家自然科学基金项目(31471660)

摘　　要：目的:探讨食源性金黄色葡萄球环丙沙星耐药性的形成与gyr A和grl A基因突变的关系。方法:采用纸片扩散法和E-test法测定来源于上海市的135株食源性金黄色葡萄球菌对环丙沙星的药物敏感性和最低抑菌浓度(MIC),采用PCR技术扩增gyr A和grl A基因并测序。运用同源比对方法分析敏感菌株和耐药菌株在这两个基因序列上的差异性。结果:135株食源性金黄色葡萄球菌对环丙沙星的耐药率达36.30%,gyr A和grl A的携带率均为93.33%,gyr A和grl A的突变率分别为37.30%和53.97%。结论:食源性金黄色葡萄球菌对环丙沙星的耐药性的形成与gyr A和grl A的突变密切相关,环丙沙星等喹诺酮类药物作用于金黄色葡萄球菌的首要靶位点是拓扑异构酶IV。如果仅grl A发生突变,则导致该菌株低水平耐药性的形成;如果gyr A和grl A同时发生突变,就导致金黄色葡萄球菌高水平耐药性的形成。Objective： To reveal the correlation between eiprofloxacin-resistance and mutation on gyrA and grbt genes in 135 food-borne Staphylococcus aureus isolates from Shanghai. Methods： Disk diffusion method and E-test method were used to detect the susceptibility and MICs against ciprofloxacin. The gyrA and gr/A genes were amplified by PCR method. The fragments of gyrA and grlA gene were sequenced and then further analyzed their homology by sequence alignment. Results： The frequency of resistance to eiprofloxacin was 36.30% in 135 isolates, the frequencies of both gyrA and grbt appeared in these isolates were 93.33%, and the mutation frequencies of these two genes were 37.30% and 53.97%, respectively. Conclusion： The resistance to ciprofloxacin was closely related to the gyrA and grlA mutation. The enzyme of topoisomerase IV was the first target of ciprofloxacin. A single locus mutation of grbi was responsible for the formulation of low resistance, while mutation in both gyrA and grlA could result in high level resistance.

关 键 词：金黄色葡萄球菌 环丙沙星 耐药 突变 食品 

分 类 号：TS201.3[轻工技术与工程—食品科学]